Low-voltage excited blue phosphor and method of preparing...

Details Low-voltage excited blue phosphor and method of preparing... Low-voltage excited blue phosphor and method of preparing...

2000-03-06

2001-11-27

Koslow, C. Melissa (Department: 1755)

Compositions

Inorganic luminescent compositions

Zinc or cadmium containing

Reexamination Certificate

active

06322725

ABSTRACT:

CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to Korean patent application No. 99-7972, filed on Mar. 10, 1999, the content of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a low-voltage excited phosphor. More particularly, this invention relates to a low-voltage excited blue phosphor of high brightness and a method of preparing the same.
BACKGROUND OF THE INVENTION
In low-voltage driving display devices, such as vacuum fluorescent display devices, field emission display devices, or the like, ZnS:Zn phosphor is generally used as a blue phosphor. The brightness of ZnS:Zn phosphor is generally high, but it has a relatively short life-time. Therefore, oxide compounds, which have relatively low initial brightness but long life-times and good brightness-maintaining properties, have been recently developed for use as a blue phosphor. Among the oxide compounds, zinc gallate phosphor is known to have high brightness, and it is known to radiate a stable blue ray. Zinc gallate phosphor is also capable of radiating visible ray without an activator.
FIG. 2
shows the method of preparing the conventional zinc gallate phosphor. As shown in
FIG. 2
, ZnO, Ga
2
O
3
, and Li
3
PO
4
as a flux are mixed and fired for 3 hours at 1200° C. under air atmosphere. After the firing step, the fired matrix is milled, preferably by ball-milling to uniformly disperse the matrix. Then to remove excess Li
3
PO
4
, the dispersed matrix is washed with nitric acid. The washed matrix is subjected to secondary firing for 1-3 hours at 1100° C. under a reduced atmosphere and sieved to produce a low-voltage excited blue phosphor. However. the brightness of this zinc gallate phosphor is low, and a phosphor of high brightness is still required in the industry.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a low-voltage excited blue phosphor of high brightness. It is another object of the present invention to provide a method of preparing the low-voltage excited blue phosphor of high brightness.
In order to achieve these and other objects, the present invention provides a low-voltage excited blue phosphor comprising a ZnO.Ga
2
O
3
matrix and Bi doped in the matrix as an activator. The present invention also provides a method of preparing a low-voltage excited blue phosphor comprising the steps of mixing ZnO, Ga
2
O
3
, a Bi compound, and a flux to produce a mixture, and firing the mixture at 1100-1300° C. to produce a fired material. The fired material is milled and washed with an acid. The washed material is then subjected to secondary firing at 800-1100° C. and sieved to produce the blue phosphor of the present invention.

Affiliated with

Also associated with

Rating

Low-voltage excited blue phosphor and method of preparing... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Low-voltage excited blue phosphor and method of preparing..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low-voltage excited blue phosphor and method of preparing... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2588424